Why Do Bubbles Burst?

One of the great joys of blowing bubbles is getting to burst them. But, what is going on when a bubble pops? Why do they burst?

As we discussed earlier, bubbles are spherical due to air pressure pushing against the surface tension created by a bubble’s water molecules.

These two forces create a very fragile equilibrium that can be broken quite easily. If a hole is created on the surface of the bubble, the air pressure within the bubble will escape, and the water molecules — now with no force pushing from within — will collapse by folding back on its self.

What Will Cause A Bubble to Pop?

Anything that fractures the tenuous layer of water molecules can cause a bubble to burst. For example, a gust of wind or an object (like your finger) will easily cause a bubble to burst. Also, a bubble will burst if enough of the water molecules evaporate.

However, the force must be enough to break the surface tension. A nail will usually pop a bubble. But, if the nail is wet, and the bubble is thick enough, you can pierce a bubble many times without it popping. The water on the nail gives the water molecules in the bubble something to hold onto so the bubble will remain intact.